Breathing device for storage tanks



BREATHING DEVICE FOR STORAGE TANKS 3 Sheets-Sheet 1 Filed July 24, 1947m m m m HAROLD A. OUIST ATTORNEYS April 1, 1952 H. A. QUIST 2,591,098

BREATHING DEVICE FOR STORAGE TANKS Filed July 24, 1947 3 Sheets-Sheet 2IN V EN TOR.

HAROLD A. QUIST BY ATTORNEYS April 1, 1952 H. A. QUIST 2,591,098

BREATHING DEVICE FOR STORAGE TANKS Filed July 24, 1947 5 Sheets-Sheet 3INVENTOR.

HAROLD A. QUIST ATTORNEYS Patented Apr. l, 1952 BREATHING DEVICE FORSTORAGE TANKS Harold A. Quist, Elkton, Md., assignor to Sun Oil Company,Philadelphia, Pa., a corporation of New Jersey Application July 24,1947, Serial No. 763,347

4 Claims. 1

The present invention relates to improvements in breathing devices forstorage tanks, and more particularly, to valves for sealing and ventingfluid storage tanks under changing conditions of pressure and vacuum.

It is an object of the invention to correct pressure variations in bulkstorage tanks in response to fluctuations of pressures within thestorage container.

Another object is to maintain the operating pressure of the bulk tankuntil a condition of unbalance is reached and preventing spasmodicexhausting of the pressure to the atmosphere causing chattering andrapid movement of the valve by releasing the internal pressure to apredetermined point below normal operating pressure.

A further object is to utilize both the static and velocity pressureheads of either positive or negative pressure diiferences to perform acom plete venting function with fewest operations of the valve.

Still another object is to disclose a valve member for use with tankbreathers, as herein described, which is pivoted about the longitudinalaxis thereof and will respond in a positive manner to pressure changesin the storage tank.

Yet another object is to disclose a tank breathing valve which operatesin a sealing medium, the medium level being controlled by pressurevariations within the bulk storage tank with which the venting valveoperates and transmitted through a reservoir of such sealing medium.

Still a further object is to insure the uninterrupted operation of thiscylindrical valve member by suspending it to rotate about itslongitudinal axis on knife edge bearings of unique and efficient design.

Other objects of this invention, including certain features forutilization of pressure differences and provisions for quick closingaction after pressures have been balanced, will be best understood fromthe following description of one illusstrative embodiment of theinvention, taken in connection with the appended claims and theaccompanying drawings in which:

Figure 1 is a plan view, partly broken away, of the breathing device.

Figure 2 is a sectional elevation with parts removed.

Figure 3 is a perspective view of the cylindrical valve member.

Figure 4 is a pictorial representation of the pivot bearing.

Figure 5 is a sectional view of the reservoir attachment, and

Figures 6, 7 and 8 are sectional views along line 6--6 or Figure 2showing the cylindrica valve member in operating positions.

A description of the parts of the breather device will requireconsideration of Figures 1, 2, 3, 4 and 5 of the drawings where likeparts are in dlcated by like numerals, while the operation will refer toFigures 6, 7 and 8 where the parts are also similarly numbered.Referring now. to Figures 1, 2 and 3, housing It supports thecylindrical valve member I I on pivotal members I2, the knife edges ofwhich are aligned in prolongation of the longitudinal axis of thecylindrical valve member I I and are submerged below the sealing liquidlevel. Rectangular conduit I3 ber 11.

connects the vapor space M of the storage tank I5, passing through asealing liquid IE and projects into the body of the cylindrical valvemem- The pressure transfer pipe I! connects the vapor space I4 of tankI5 through conduit I3 to the valve activating chamber I8 of valve memberI I.

In addition to the valve activating chamber I8, the cylindrical valvemember II, shown in perspective in Figure 3, may be considered asincluding two additional chambers. A pressure release chamber I9 is opento vent positive pressures to the atmosphere and another, the vacuumrelease chamber 20, admits atmospheric pressure to the storage tank I 5when a vacuum is created during operation. In the normal position vacuumrelease chamber Zil acts as a seal, as will be described later indiscussing the operation of the breather. Weight suspension brackets ZIare fastened to the cylindrical valve member I I below sealing liquidlevel in thenormal position to keep the bar weight 22 free underfreezing conditions or gumming action of escaping gases. When weight 22is not supported by brackets 2| it is retained by similar brackets 23 inposition for engagement with brackets 2i as required by the operation ofthe valve. Balance weights 24 are attached at each end of thecylindrical valve member I I which are readily adjusted to keep therotatable valve of the breather device in operating balance. To attainthe desired delayed action after balancing internal tank pressures andto insure positive closing action, weight 2'1 is attached to therotating valve member l I as shown.

Figure 4 pictorially represents the pivot suspension generallydesignated as I2 in Figures 1, 2 and 3. In the preferred embodiment itcomprises a knife "edge member is adapted to be attached to thecylindrical valve member Ii as shown in Figure 3. Returning to Figure 4,member 40 is characterized by two separate, knife edge bearings ll and12 which are in alignment with each other and, as fastened to valvemember II, are also in alignment with the longitudinal axis of thecylinder. The bearings are attached so that they are immersed in thesealing liquid i5, thereby preventing interference of operation byfreezing or gumming through the action of released gases. A supportbearing 43, widely notched at 44, receives knife edge bearing 4| as itthrusts downwardly, suspending the weight of cylindrical valve member i5. An anchor bearing 45 looks knife edge bearing 42 in wide notch 46,thereby counteracting the up-thrust caused by rotation and pressure,preserving alignment and insuring continuous positive breathing action.The shape of bearing as illustrated, showing a slot 4? to receive theanchor bearing 45, is a preferred embodiment of this pivotal member andmay be changed to many different shapes still retaining the spirit ofthe disclosure. 7 Accurate alignment is obtained more readily by the useof elongated bolt holes 48 and 49 in members 43 and 45 respectively.

A closed reservoir tank 60 is shown in operating-position in Figures 1and 2 and in detail in Figure 5. A stopper 5! is shown in the top oftank 60, thereby enclosing the suppl of seaiing fluid and subjecting itto pressure variations to be described with the breather operation. Thetank 60 is filled at necessary intervals by pouring the liquid throughthe stopper opening as required. For ordinary purposes a light oil whichwill not freeze and which has been treated with a fire proofing liquidis most satisfactory for use as a sealing fluid. A liquid supply pipe 62connects the reservoir tank 6i) with the liquid seal in housing 0 at apoint below the maintained level of the sealing'liquid. Valves 63 and 65close pipes 62 and 64 while removing plug BI and filling tank 60. Asecond tube 84, with valve 65, connects tank 60 with pressure equalizingchamber 66, also extended to a position below the maintained liquidlevel. Pressure equalizing chamber 66 is positioned with relation to themaintained liquid level of sealing liquid H5 in chamber It to bepartially filled with liquid and to have a sealed vapor or pressurespace 61 above that level. A tube or pipe 58 connects the closedpressure space M with the vapor space I4 making the liquid levelrespons'ive to pressure changes in the attended storage tank [5. Anoverflow 69 is attached to vapor space 61 and is trapped or sealed toretain the pressure as conventionally illustrated by submersion in fluidin container it.

The operation of the breather device, described in detail above, willnow be readily understood by reference to Figuresfi to 8 inclusive.These figures are sectional views along line 6 in Figure 2 and show therotated positions or the cylindrical valve member H during the breathingoperations of the storage tank which the device attends. Figure 6illustrates the cylindrical valve member II, positioned in housing toenclose the projection of conduit [3 above the sealing fluid It in thenormal position. The conduit 13 transmits the pressure variations fromthe vapor space of storage tank l to the vacuum release chamber 29within the cylindrical valve member II, where a sealed conditionattainsby cooperation of the valve cylinder with the surface of thesealing liquid. By selection and adjustment of balancing weights 24 and21,

and bar weight 22, the valve member H can be operated within wide rangesof pressure variations.

4 Figure 7 illustrates the valve member function ing under'pressureconditions which may arise within a storage tank because of additionalquantities of stores being pumped in, expansion or volatility due totemperature changes, and

other conditions. The pressure within conduit l3 increases as well as inpressure transfer pipe 5?. Arcuate valve actuating chamber it; receivesthe pressure from pipe ii and causes cylindrical valve member I l torotate about the longitudinal axis. As the valve member rotates, anincreased. cross-sectional area of chamber 8 with its attendant bearingsurface 25 is presented to the pressure action from pipe ll causing thevalve to rotate rapidly and positively to the pressure relievingposition. The valve starts to rotate slowly exerting force on weight Elwhich is at a maximumlever arm distance from the center of rotation ofvalve member H. As pressure causes the valve member to rotate theeffectiveness of weight El decreases and the valve oper-- ates morerapidly. In closing the valve, the reverse is true and a positiveclosing action is obtained. Reference to Figure 7 will disclose chamberl9 as now lifted from the sealing liquid 16 and venting freely to theatmosphere, indi:

cated by the arrows. The static pressure head withinthe vapor space ofthe storage tank now moves to escape setting up a velocity pressurecomponent. Pressure transfer pipe ll let into the path of the releasedpressure in conduit H, as illustrated, receives the impact of thevelocity pressure and transmits it to chamber 18. where it keeps thevalve member l l in an open position beyond that required to merelyrelease the static pressure head. Consequently, the reduction inpressure in the storage tank vapor space is carried below that requiredto permit the valve to rotate to the closed position, and the resultantaction is positive to the closed position. again assisted by weight 21,without chattering common to the devices described in the prior art.

Vacuum conditions within the vapor space of the storage tank arise wherestored liquids are being pumped out or reductions in temperature causecontraction and condensation of volatile liquids. Under theseconditions, a negative pressure or vacuum is created which must bebalanced with atmospheric conditions to avoid danger to personnel andinjury to equipment. Figure 8 illustrates the rotation of the valvemember to release a vacuum condition. The negative pressure in thestorage tank vapor space causes a similar condition in chamber l8.Arouate chambers l8 and is and weight 21 increase the tendency of thevalve to revolve about the longitudinal axis and when not supported bynormal predetermined'pressure cause the cylindrical valve member H torotate opposite to the pressure rotation and lift chamber 25 from thesealing liquid It to receive pressure for transmission through conduitI3 to the vapor space. Weight 21, in this operation, increases theopening action by increasing the'le'v'er arm'.

by brackets 23 on the inside of housing Land is picked up by brackets 2|on the periphery of the valve member as it rotates to vent the vacuumcondition. It will be noted that the bar weight 22 is inactive duringthe pressure vent-' ing operation. To obtain a positive action of thevalve, free from chattering and repeated useless operation to gainpressure balance, similar to the use made of velocity pressure head inthe pressure release function described above, lip 26 is attachedperpendicularly to the tangent on the lower edge of arcuate vacuumrelease chamber 20. In the vacuum release position, lip 26 is liftedfrom sealing liquid l6 and presents a surface large enough in area, torespond to the velocity pressure head of the atmosphere pushing in tosatisfy the vacuum. This velocity pressure head continues operationbeyond the requirements of the vacuum condition due to the motion of theair moving toward the vacuum, and insures the firm and steady seating ofthe valve member. Arrows have been added to this figure as well, toassist in a full understanding of the breather device operation.

The sealing liquid IS in housing It, Figures 1, 2 and 5 is maintained ata predetermined depth to preserve a seal with the cylindrical valvemember II and prevent venting until the conditions are such as torequire positive action. The level of the sealing liquid is preserved bya supply in reservoir 60 which forms part of the housing body. Stopper6i closes the reservoir and retains the fluid supply therein byatmospheric pressure on the fluid surface in housing In and the pressurein equalizing chamber 66.

Under conditions of positive pressure as con-' trasted with vacuum,existing in vapor space I4, referring to Figure 2, the pressure istransmitted upwardly in tube 58 to the space $1 in chamber 56. Theliquid level in chamber 66 will be forced down and, if there is notsuflicient liquid in the system, the under edge of tube 64 will be abovethe liquid level thus permitting vapors under pressure to enter chamberBil displacing liquid and thus causing a limited quantity of liquid tomove downward to chamber Ill. The pressure will also be transmittedthrough overflow pipe 69 to liquid seal i6 where the design is such asto present an effective seal under all operating conditions. If theliquid seal level is at the predetermined depth the lower end of tube 64projecting downward into chamber 66 will not be exposed and,consequently, the Vapor in chamber 66 will not be permitted to risethrough tube 64 to reservoir 60.

Where a negative pressure or vacuum exists in tank l5, the vacuum istransmitted to equalizing chamber 65 where under extreme conditions theliquid will rise about tube 64 and spill into overflow pipe 69. Thiscondition exists only when there is too much liquid in housing l0.Within housing Ii] immediately preceding the rotation of valve member Hto release the vacuum as shown in Figure 8, the atmospheric pressurewill force the liquid seal to rise in chamber 20 of the valve member I land depress the level about the mount of tube 62. Under theseconditions, if there is not sufficient liquid and the mouth of tube 62is exposed to the air, atmospheric pressure will force air upwardthrough tube 62 to reservoir 60, thereby releasing sufiicient liquid tosupply the deficiency.

The construction and operation disclosed herein illustrate the preferredembodiment of a storage tank breathing device. It is not intended thatthe details described be regarded as limitations upon the scope of theinvention except in 6 so far as is included in the accompanying claims.-

I claim: 1. A breathing device comprising in combination; a housingadapted to contain sealing liquid having a normal level therein; aninverted open sided valve member pivotally mounted in said housing foroscillating movement from an intermediate position in oppositedirections, said member being positioned in said housing when it is inits intermediate position so that both edges are below the normal liquidlevel and thereby submerged in the sealing liquid and when oscillated inone direction one edge is below the normal liquid level and the otheredge is above the normal liquid level to form a vacuum relief chamber,and when oscillated in the other direction the said one edge is raisedabove the normal liquid level to provide a pressure relief passage, aconduit extending from the exterior of said housing thereinto and to apoint above the normal liquid level and within said valve member andadapted to be connected to a source of pressure; and a separatepivotally mounted oscillatable operating chamber secured to said valvemember for oscillating the same in either direction, said operatingchamber having two ends, one of which is sealed to the atmosphere andprojects above the normal liquid level at all times during itsoscillating movements and the other being open and positioned below thenormal liquid level at all times during its oscillating movements; and asecond conduit being adapted to be connected to the same source ofpressure as said first conduit and extending into said operatingchamber.

2. A breathing device as set forth in claim 1 further including meansfor supplying liquid to said housing for maintaining the sealing liquidat the normal liquid level.

3. A breathing device as set forth in claim 2 wherein the liquid supplymeans includes a closed liquid reservoir mounted adjacent said housingand positioned above the normal liquid level therein, a closed pressureequilizing chamber positioned below said reservoir and in com municationwith said housing at a point below the normal liquid level, conduitconnections between said reservoir and said housing and between saidreservoir and said pressure equalizing chamber, a conduit extending fromsaid pressure equalizing chamber and adapted to be connected to the samesource of pressure, and an overflow conduit from said pressureequalizing chamber.

4. A breathing device comprising in combination, a housing containing asealing liquid, an open sided cylindrical valve member pivotally mountedalong its longitudinal axis parallel to the surface of the sealingliquid for oscillatory movements about said axis, said member beingpartially submerged in the sealing liquid to form a vacuum reliefchamber, a pipe extending from the exterior of said housing to a pointabove the liquid level within said cylindrical member, a first arcuateplate on said member and extending in spaced relation along a portlonofsaid cylindrical valve member to form a pressure relief passage open atone end to the interior of the cylindrical member and open at the otherend to the atmosphere, a second arcuate plate attached to and extendingalong a portion of said first plate cylindrical member and said firstmentioned arcuate plate, respectively, cooperating with the sealingliquid to control the supply and exhaust of fluid to and from said pipeas the cylindrical member oscillates in response to pressure changes 5in said pipe.

HAROLD A. UIST.

REFERENCES CITED The following references are of record in the 10 fileof this patent:

UNITED STATES PATENTS Name Date Moore Feb; 2, 1897 15 Number NumberNumber

1. A BREATHING DEVICE COMPRISING IN COMBINATION; A HOUSING ADAPTED TOCONTAIN SEALING LIQUID HAVING A NORMAL LEVEL THEREIN; AN INVERTED OPENSIDED VALVE MEMBER PIVOTALLY MOUNTED IN SAID HOUSING FOR OSCILLATINGMOVEMENT FROM AN INTERMEDIATE POSITION IN OPPOSITE DIRECTIONS, SAIDMEMBER BEING POSITIONED IN SAID HOUSING WHEN IT IS IN ITS INTERMEDIATEPOSITION SO THAT BOTH EDGES ARE BELOW THE NORMAL LIQUID LEVEL ANDTHEREBY SUBMERGED IN THE SEALING LIQUID AND WHEN OSCILLATED IN ONEDIRECTION ONE EDGE IS BELOW THE NORMAL LIQUID LEVEL AND THE OTHER EDGEIS ABOVE THE NORMAL LIQUID LEVEL TO FORM A VACUUM RELIEF CHAMBER, ANDWHEN OSCILLATED IN THE OTHER DIRECTION THE SAID EDGE IS RAISED ABOVE THENORMAL LIQUID LEVEL TO PROVIDE A PRESSURE RELIEF PASSAGE, A CONDUITEXTENDING FROM THE EXTERIOR OF SAID HOUSING THEREINTO AND TO A POINTABOVE THE NORMAL LIQUID LEVEL AND WITHIN SAID VALVE MEMBER AND ADAPTEDTO BE CONNECTED TO A SOURCE OF PRESSURE; AND A SEPARATE PIVOTALLYMOUNTED OSCILLATABLE OPERATING CHAMBER SECURED TO SAID VALVE MEMBER FOROSCILLATING THE SAME IN THE DIRECTION, SAID OPERATING CHAMBER HAVING TWOENDS, ONE OF WHICH IS SEALED TO THE ATMOSPHERE AND PROJECTS ABOVE THENORMAL LIQUID LEVEL AT ALL TIMES DURING ITS OCILLATING MOVEMENTS AND THEOTHER BEING OPEN AND POSITIONED BELOW THE NORMAL LIQUID LEVEL AT ALLTIMES DURING ITS OSCILLATING MOVEMENTS; AND A SECOND CONDUIT BEINGADAPTED TO BE CONNECTED TO THE SAME SOURCE OF PRESSURE AS SAID FIRSTCONDUIT AND EXTENDING INTO SAID OPERATING CHAMBER.